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CONCENTRATION OF URANIUM ORES
ArticleName Uranium leaching at hydrometallurgical plant of “Priargunsky Industrial Mining and Chemical Union” JSC with application of manganese dioxide and nitric acid
ArticleAuthor Litvinenko V. G., Sheludchenko V. G., Filonenko V. S.
ArticleAuthorData

“Priargunsky Industrial Mining and Chemical Union” JSC (Krasnokamensk, Russia):

Litvinenko V. G., Chief Technologist, Doctor of Engineering Sciences, e-mail: LitvinenkoVG@ppgho.ru

Sheludchenko V. G., Deputy Head of Central Research Laboratory, Candidate of Engineering Sciences

Filonenko V. S., Head of Chemical and Toxicological Laboratory (Central Research Laboratory)

Abstract

Expensive manganese concentrate is used as an oxidant during the agitation uranium leaching. Decreasing of consumption of this concentrate or its replacement by another reagent is an urgent task. The following operations became the purpose of the carried out semi-industrial testings:
— stepwise decreasing of MnO2 consumption with introduction of nitric acid, which has been earlier used for the equipment passivation into the process;
— decreasing of the range of agitation leaching of raw materials;
— increasing of uranium leaching into the solution.

Concentration of sulphuric acid was stepwisely increased from 40 to 80 g/dm3 with corresponding change of flows ratio and provision of pH of leached pulp within 1.2–1.8. This process was carried out for the following operations:
— choice of optimal and steady mode of sulphuric-nitric acid processing of raw materials during the first stage of uranium leaching;
— maintenance of redox process at the level of 700 mV.
During the experiments for raw materials opening with replacement of MnO2 by nitric acid, there was substantiated, that steady redox process with application of HNO3 and opened ore iron is maintained, taking into account the acidity of 65– 70 g/ dm3 and redox process, regulated by the acid dosage at the level of 690– 710 mV. In comparison with operating scheme of hydrometallurgical plant, the technology of sulphuric-nitric acid opening of raw materials during the processing of ores with ~0.12% of uranium content makes it possible to do the following operations:
— decreasing of MnO2 consumption by 80–95% (from ~4.8 to 1.0–0.7 kg/t);
— increasing of uranium extraction into the solution from ~91.1 to 92–93.5% during the increasing of HNO3 consumption from ~0.4 to 1.3–1.6 kg/t.

keywords Uranium, ore, pulp, leaching, oxidant, sulphuric acid, nitric acid, consumption, extraction
Language of full-text russian
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